Process of making multiple-piece springs



Patented Sept. liti),

'terasse onirica,

JOHN' F. OCONNOBQOE CHICAGO, ILLINOS, ASSIGNOR TO WILLIAM H. MINER, OF

CHAZY, NEW YORK.

PROCESS OF MAKING- MULTIPLE-PIECE SPRNG-S.

Application filed March 10,1921. Serial No. 451,238.

To all whom. t may concern Be it known that l, JOHN F. OCoNNoR, acitizen of the United States, residing at Chicago, in the county of Cookand State of illinois, have invented a certain new and usefulImprovement in Processes of Making Multiple-Piece Springs, of which thefollowing is a full, clear, concise, and exact description, referencebeing had to the accompanying drawings, forming a part of thisspecification. n

This invention relates to improvements in process of makingmultiple-piece spring.

In certain shock absorbing mechanisms, particularly those employed inrailway draft riggings, 'it is customary to use coil springs formed ofheavy rods.- Due to the limited space within which such shock absorbing`mechanisms are accommodated and the short stroke of the coupler whichispermitted, generally 2i to 292, it is impossible to obtain the necessarycapacity from springs alone to cushion the blows ,which encountered inpresent day railway service. Consequently, it has been necessary toaugment t-he spring capacity by the use of friction creating elements,this art having now been developed to a. very high degree.

For a friction shock absorbing mechanism to be successful in present daypractice for railway draft riggings, it is necessary that the device becapable of absorbing shocks of 200,000 to 400,000 pounds. The maximumcapacity of the springs employed in such devices has heretofore rangedbetween 30,000 and 40,000 pounds per spring unit. In some types ofdevices only one spring unit isemployed and in others two spring unitsso that the capacity which must be developed in the friction devicesranges from a minimum of approximately 160,000 pounds to a manimum ofapproximately 370,000 pounds. It has long been recognized thatheavy dutysprings of the character indicated without requiring excessive fiberstresses, having a larger capacity than above described, are desirablein order that less work may be required of the friction devices andthereby prolong the life of the shock absorbing mechanisms.

lt has also long been recognized that a helically coiledspring having aplurality of turns does not have anyl greater capacity than a spring ofsimilar pitch, similar coil diameter and similar material having only asingle turn although the strokes or compression movements of the twosprings may vary. It is therefore possible to obtain a spring of double,triple or even greater capacity. without changing the pitch, coildiameter, size of the material forming the spring, or increasing thefiber stresses by making the spring in a multiple of pieces and allowingadjacent turnsy of the pieces to lie in line contact throughout arcs ofsubstantially 360.0, the capacity of such multiple-piece springs beingdependent upon the number of such turns which are in line contact.

The object of my invention is to provide a very simple method or processof making such multiple-piece springs having greater capacity than thepresent type of continuously coiled spring and whereby the samemachinery lnow employed in ceiling the present types of springs may beutilized without modification.

ln the drawing forming a part of this specification, lrhave illustratedthe steps employed in my improved process for manufacturing amultiple-piece spring of the type indicated. ln said drawing, Figure lis an elevational view of a length of cylindrical rod cut to properlength for coiling into a continuous helical spring having an overalluncompressed length greater than the desired over-all uncompressedlength of the finished multiple-piece spring. Figure 2 is a view similarto Figure 1 showing the first step in the process of making the springand wherein the ends of the'rod are tapered to provide the usual fiatends for the coil spring.

`Figure 3 is an elevational view of a continuously coiled helical springformed from the rod illustrated in Figures l and 2. In Figure 3 isillustrated two lines of severance of the coil in order to obtain themultiplepiece finished spring which, in the instance shown, containsthree pieces. And Figure lis a view similar to Figure 3 illustrating thecompleted multiple-piece spring.

In carrying out my invention, I first cut off a section of rod A to thedesired length, said rod being of cylindrical form and of the desireddiameter and material. The rod A is then tapered or flanged at itsvendsto the form indicated at A in FigureQ, the beveled ends being shown at10-10, the same being oppositely disposed at the ends of the rod so asto brino the tapered tangs of the finished spring in proper position.lThe tapering of in such manner as to bring the tapered ends the ends ofthe rod to the form shown at A in Figure 2 may be done in any suitablemanner, preferably by a trip hammer while the rod is ata hightemperature. y 'f After the rod A has been formed as shown in Figure 2and while still at a high temperature, it is then coiled into acontinuous helix of the desired pitch, and 4coil diameter to the formshown at A2 in Figure 3, this step being carried out' by any one of thewell known types of spring coiling machines and 10-10 as Vshown and thusprovide flat bearingv surfaces at each end of the spring. .Where themultiple piece spring is to consistxof three vpieces as shown in Figure4l,

the spring as initially' formedina continuous heliX as shown at A inFigure 3, will have an over-all length, uncompressed, equal to that ofthe desired over-all ylength of the finished springplus twice the spaceas indicated at 11 betweeneach turn 'of the helix. Then the springis inthe form shown at A2 in Figure 3, it will be temperedand tested in theusual manner. a v.

The'nal step in the process consists in 'cutting orsevering thecontinuous helix into three parts atl two places intermediate lthe endsof the Ecoil as indicated yat 12-12 in .Fi'ure3, the lines of severancebeing prefegrzibly in lplanes `perpendicular to the axis of theycoil-.forming rod. .l The cutting or severance of the coil into thethreepieces indicated may be done by .use of an electric arc, oiryacetyleneflame for other desired means. Severing of the coil into the threepieces whichmay be designated as A3, A4, and A5 results inthe end piecesA3' and A? having their inner ends squared as indicated at 13--13and the`intermediate piece A4 with both of itsv ends squared as indicatedat14-11- After`:the three individual ypieces are formed las aboveindicated, they are nested so that the vinnermost turn or coil 15 of theend piece Asiis in line contact throughout an yare of substantially 360Dwith the adjacent end turn or coil 16 of the intermediate piece A4.Similarly, the innermost turn or coil 17 .of the other end piece A5 isvin continuous line contact throughout an yFigure 3, due to the linecontacts between thev adjacent endcoils of the parts as hereinbeforedescribed. The compression stroke or movement of the finished springshown in Figure 4 will correspond to fivespaces between turns ascompared to a stroke corresponding to seven ofsuch spaces in a spring ofthe continuous type such as shown `in Figure 3. .As will be obvious tothose skilled in the art, 'various combinations of capacities andcompression stroke may be made by yvarying the numbers of pieces and thenumbers of turns ywhich are allowed to be nested in line to linecontact. Thefinished spring shownin Figure 4 has theflat bearing ends ascustomaryin heavy duty springs of the type referredy to; its length maybe made such as to adapt it to presentwspaces allowed for springs ofthis type; and it is evident that the cost' of `manufacture is notvappreciablygreater than that of springs of the present continuouslycoiled type.

'I have illustrated and described' the procn an inner lightery nestedcoil as 'shown in the drawing in connection with the. usual outerheavycoil. Y f

I have herein shown and described what I now consider the preferredmanner of carrying outfthe invention, but' the same is merelyillustrative and I contemplate all changes and modifications that comewithin the scope of the claims appendedV hereto.

I claim: 1

1. The herein described process of making a multiplenpiece, helicallycoiled spring wherein adjacent turns of the pieces are in line contactforvapproximately 360 which consists in "forming a single vpiecehelically coiled spring consisting of a plurality of continuous, axiallyspaced turns of the desired pitch andcoil diameter and of anuncompressed over-a'll length greater than that of the desired finishedmultiple-piece spring; then serving oneof theintermediate turns of saidcoiled initially formed spring; and then nesting the-pieces `so formedAwith adjacent turns of the severed pieces in line contact throughout anare of substantially 3600.

2. The herein described processof making a multiple-piece helicallycoiled spring wherein adjacent turns of therpieces are in line contactfor approximately 3600, which consists in: forming a single piece,helically coiled spring consisting of a .plurality of continuous,axially spaced turns of the de-v sired pitch and coil `diameter and ofan uncompressed over-all length greater than the uncompressedover-alllength of the desired finished ymultiple-piece spring; thensevering one ofthe intermediate turns of said coiled i initially formed,springy in a plane substantially perpendicular to the vaxis lof thecoilforming material; and finally nesting the pieces so formed Withadjacent turns of the severed pieces in line contact throughout an arcci?y substantially 3600.

3. The herein described process of making a multiple-piece, helicallycoiled spring wherein adjacent turns of the pieces are in line Contactfor approximately 360 and the ends of the spring provided With fiatbearings, Which consists in: providing a rod of the desired material andsuitable length; oppositely tapering the ends of said length of rodmaterial; then coiling said rod into a single piece helical springconsisting of a plurality of continuous, axially spaced turns of thedesired pitch and coil diameter and with the tapered ends of thc rod toprovide flat bearings; then severingone of the intermediate turnsof saidcoiled initially formed spring; and inally nesting the pieces so formedwith adjacent turns ofthe severed pieces in line contact. 1 o

4. The herein described process of making a multiple-piece, helicallycoiled spring wherein adjacent turns of the pieces are in line contactfor approximately 360 and the ends of the spring providing Hat bearings,which consists in: rst providing a section of rod material of thedesired length and quality; then oppositely tapering the ends of saidsection of rod; then coiling said section of rod into a continuous helixof desired pitch and coil diameter With the tapered ends so arranged asto rovide flat bearings at the ends of the he iX; tempering the coil soformed; then severing one of the intermediate turns of said continuouslycoiled spring in a plane substantially perpendicular to the coil-formingrod; and finally nesting the pieces so formed with adjacent turns of thesevered pieces'in line contact throughout an arc of approximately 3600and With the severed ends of the pieces `abutting each other.

In Witness that I claim the foregoing I have hereunto subscribed my namethis 21st day of Feb., 1921.

' JOHN F. OCONNOR. Witnesses:

CARRIE GAILING, UNA C. PERIN.

